Does Kafka 0.8.2 producer has a lower throughput in sync-mode, comparing with 0.8.1.x?

[Yu Yang]

Hi,

Kafka 0.8.1.1 allows us to send a list of messages in sync mode:

    public void send(List<KeyedMessage<K,V> messages);

I did not find a counter-part of this api in the new producer that is
introduced in kafka 0.8.2. It seems that  we can use the following method
to do sync send in kafka 0.8.2:

    producer.send(new ProducerRecord(...))).get();

My understanding is that we can only send one message at a time in
sync-mode. This will limit the throughput of kafka producer. Is there a way
to send a batch of messages in sync mode using kafka 0.8.2 producer?  Is
there any study on the throughput of Kafka 0.8.2 producer, comparing with
kafka 0.8.1.1?

Thanks!

Regards,
Yu